In a communication process, a mobile communications system generally needs to perform clock synchronization. When a base station in a mobile communications system acquires clock information, generally, a clock needs to be transmitted by installing a global positioning system (GPS, Global Positioning System), or installing a relative global positioning system (RGPS, Relative Global Positioning System), or using a communications network, for example, adopting an IEEE 1588 V2 clock synchronization protocol. A GPS antenna receives a signal and transmits the signal to the base station through a cable, and the clock is recovered through a satellite card. Because signals from more than four GPS satellites need to be received during clock recovery, the GPS antenna needs to be installed at a position with a broad view in the air, and the GPS is connected to the base station through the cable. The RGPS is integrated with an antenna, a satellite card, and a recovery clock (which is equivalent to a time/clock source), and is connected to the base station through the cable. The GPS antenna is directly connected to a satellite card of the base station, and the base station recovers the clock; and the RGPS recovers the clock and is directly connected to the base station.
The GPS antenna needs to be installed at a position with a broad view in the air, and needs a separate cable for connection during the installation; and the RGPS needs to be installed at a position with a broad view in the air, and also needs a separate cable for connection during the installation, thereby resulting in a waste of a cable and complex installation.